Stratified coastal ocean interactions with tropical cyclones

Scott Glenn, Travis Miles, Greg Seroka
Rutgers University
Noon Mar 22 in Room 2155

Abstract:
Hurricane intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during Hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 C and up to 11 C) over a wide swath of the Mid-Atlantic Bight continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene’s accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. .